In color printers a plurality of color planes are sequentially aligned and deposited onto a transfer media such as a transfer belt. The transfer belt is then used to transfer the accumulated color planes to a piece of paper or other media. A problem associated with this process is misregistration or misalignment of one or more of the color planes. Alignment of the color planes and optimization of the transfer is crucial in achieving a high quality image. Due to the fact that each individual color plane is transferred onto the belt or paper at different locations along the travel path of the transfer belt, variations of the transfer quality and positioning of the belt within the travel path must be compensated for with a high degree of precision.
There are many instances where position variations and transfer quality variations can develop and cause a concomitant degradation in the resulting image. Factors such as variations in the width of the belt, the belt tension, and the belt resistivity are examples of factors that lead to transfer quality and belt position variations. It would be desirable to have a method and apparatus that compensates for variations within a printer which is inexpensive to implement and does not add complexity to the printer.
A method and apparatus for providing transfer quality optimization in printers is disclosed. A transfer belt subassembly includes a transfer belt and a storage device. The transfer belt also includes a home position indicator. The transfer belt subassembly is measured and characterized relative to the home position indicator before being installed in a printer. The measurement and calibration data for the transfer belt is then stored in the storage device that is part of the transfer belt subassembly. When the transfer belt subassembly is inserted into a printer, a controller within the printer is placed in communication with the storage device. A sensor is used to determine the home position of the transfer belt from the indicator, and a resulting signal indicating when the belt is at the home position is provided to the controller. The controller utilizes the measurement and calibration data from the storage device to provide correction with respect to each color station of the color printer, taking into account and compensating for variations in the transfer belt subassembly. In such a manner, the measurement and calibration data is predetermined before the transfer belt subassembly is inserted into the printer, thereby simplifying the printer composition. By use of the calibration and measurement data, precise alignment of the color planes with respect to one another is achieved, and the proper electrical transfer setting suited to that belt is obtained for improving transfer quality.